The frame of a snowmobile has a tunnel. Typically, the tunnel defines footrests, a seat of the snowmobile is disposed above the tunnel and a drive track propelling the snowmobile is disposed at least in part below the tunnel. The drive track is disposed around a rear suspension assembly. The drive track has a belt with a plurality of external lugs extending from an outer surface of the belt. In order to increase traction, some tracks are additionally provided with metallic studs protruding from the outer surface of the belt.
As the snowmobile operates, the rear suspension assembly compresses, expands and pivots relative to the tunnel. As would be understood, as a result of the movement of the rear suspension assembly, in addition to turning around the rear suspension assembly, the drive track moves relative to the tunnel with the rear suspension assembly.
Under some conditions, it may be possible for the rear suspension assembly to move to a position relative to the tunnel that results in the external lugs and the studs (should studs be provided) of the track to come into contact with the underside of the tunnel. This could potentially damage the tunnel.
This problem is exacerbated in tunnels defining a heat exchanger assembly through which a motor fluid, such as engine coolant or lubricant, flows to be cooled by air flowing over the tunnel and the snow projected by the track onto the tunnel. In such tunnels, should the external lugs or the studs come into contact with the portion of the tunnel defining the heat exchanger assembly, the external lugs or the studs could pierce that portion of the tunnel, resulting in loss of the motor fluid. As would be understood, loss of this motor fluid could potentially result in damages to components of the snowmobile other than the tunnel. For example, should the motor fluid be engine coolant, loss of the coolant could lead to overheating of the engine which could damage the engine.
Another solution to the above problem consists in moving the drive track and the tunnel further away from each other. However, this would raise the center of gravity of the snowmobile. As a result, the stability and handling characteristics of the snowmobile could be affected.
Accordingly, it would be desirable to have a snowmobile in which the drive track is prevented from coming in contact with the bottom portion of the tunnel.